A 45-year-old woman was admitted to our hospital because of speech difficulties. Initial magnetic resonance imaging (MRI) suggested subacute ischemic infarction in the left parietal to temporal area. Neurological examination on admission showed motor aphasia without any other deficits, and her symptoms gradually worsened with severe headaches. Nine days after admission, brain MRI revealed the development of an ischemic lesion, and magnetic resonance angiography (MRA) showed left internal carotid artery dissection. Emergency carotid stent placement was then performed on the stenotic lesion, which improved her severe headache. Based on her symptoms, she was diagnosed with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) after revascularization therapy. This is the first case in which acute endovascular revascularization was performed for internal carotid artery dissection in MELAS.